1. The Field of the Invention
This invention relates to fencing, and more particularly, to novel methods and apparatus for framing sheathed gate structures such as vinyl gates.
2. The Background Art
Gates have existed as long as fences have. Fences have existed substantially as long as the concept of private property has existed. With the advent of new materials and the decorative abilities of plastics, plastic fencing, such as vinyl, and its supporting fencing components have become popular.
Gates have limited ability to suspend from gateposts. Moreover, cantilevered structures need some type of rigid structural support. In addition, vinyl fencing systems do not typically support rigid comers. For example, stresses at comers of gates exceed the loads supportable by vinyl structures.
For many purposes, vinyl fencing is adequately strong, durable, weather resistant, structurally supportive, and the like. However, gates are moving members that are supported from a single side or end. Accordingly, substantial structural integrity is required to a greater degree in a gate than may be required from other fencing components. Moreover, since a gate may be effectively cantilevered, stresses may be substantially higher in portions of a gate, than they would be if merely supporting the weight of a fence structure directly thereabove.
Accordingly, in certain gate systems, a gate itself may be formed of a metal. Alternatively, the gate may be structurally framed of metal, covered with electrostatic powder coating, paint, or sheaths of vinyl material. Metal frames exhibit two serious difficulties, among others. Rigid frames are large, bulky to transport, heavy to handle, and problematic to inventory in a large number of size options.
Attempts to remedy the limitations of solid, prefabricated gates or gate frames, result in welds at comers of steel structures. The welds are subjected to substantial stress from twisting under windloads, slamming, eccentric loading, and various other forces incident to operation of the gate. Thus, assembled, metal, gate frames or gates lack rigidity, or else they tend to fracture at points assigned the responsibility for rigidity.
Gates enjoy another peculiarity. Since gates tend to cover a space or opening having a substantially rectangular aspect, gates are structurally not naturally rigid. That is, any four member structure (quadrilateral) is fundamentally unstable. Making a gate from a plastic serving as structural members is often untenable. Thus, a plastic fence may still require a metal gate.
Torsional rigidity is difficult in a gate, moreover, because a gate structure is typically dominated by two dimensions, a vertical dimension and a horizontal dimension, in which the gate extends. The transverse direction through the gate is typically orders of magnitude less than that of the longitudinal (vertical) or lateral (horizontal) dimension along the expanse of the gate. Accordingly, forces in a transverse direction (through the gate) typically tend to twist one comer about the next two proximate comers. Thus, gate structures often break near the comers thereof due to torsion from loading transversely through the gate against any one of the comers.
In order to obtain maximum strength and stiffness, a tubular member represents a nearly optimal configuration. Rectangular tubular cross sections and circular tubular cross sections provide very stiff structures. Tubular members may be welded and braced to form comparatively strong gates. In order to stabilize the longitudinal and lateral dimensions of a gate structure, a diagonal brace or support may extend from an upper comer (inside) near a hinging mechanism down to an opposite lower comer (outside) that swings as the gate opens. Thus, a comparatively unobtrusive but strong gate support may greatly benefit the rectangular structure.
However, the overall lifetime of a gate structure begins with production of stock materials from which to construct a gate. Many materials are long. That is, one may define an aspect ratio as a relationship of one linear dimension to another linear dimension (typically in a direction orthogonal to the first). An aspect ratio may be thought of as a ratio of the relative aspects of the two dimensions. Gates may have an aspect ratio near unity for their longitudinal and lateral and longitudinal dimensions, but much smaller or greater for others (e.g. transverse: lateral longitudinal: transverse).
When materials are shipped from a source of raw stocks or from a manufacturer of gate hardware to a reseller or customer, total shipping weight is important. Moreover, total shipping volume is important. Shipping costs may increase with excess weight or with excess volume (cubic feet). Thus, a load may xe2x80x9cgross outxe2x80x9d a hauling vehicle if the weight reaches the maximum vehicle weight permissible. A load may xe2x80x9ccube outxe2x80x9d a hauling vehicle if the volume of packaging containing goods fills the entire available volume. Ideally, a load grosses out and cubes out a hauling vehicle at about the same point (same number of products). A vehicle grossed out could carry more volume if the volume were not so heavy. A vehicle that is cubed out could haul more weight if the weight did not fill up or require so much volume.
As this applies to gate hardware, maximum structural reliability is required at a minimum weight and minimum shipping volume. Traditionally, gate frames have been manufactured as rigid structures fully assembled. Often, gate frames are welded structures for supporting other gate materials, such as slats, pickets, panels, and the like. As a practical matter, tubular steel may be formed into rectangular structures to serve as gate frames. Whereas other gate materials may be shipped as long stocks, gates become large in two dimensions. Meanwhile, the tubular steels available for welding are often very heavy, comparatively, with respect to other gate materials (especially plastics such as vinyl).
Metallic gates and metallic gate frames have heretofore been extremely heavy. What is needed is a light weight, rigid, metal-reinforced, disassembled gate framing system for vinyl gates.
Likewise, metal-reinforced or metal-framed, gates in vinyl fencing systems are typically open at some point to weather. Some gates are merely painted, others have incomplete shielding by vinyl shrouds and the like. It would be an advance in the art, and a great improvement in the technology to form a metal framing system for vinyl gates in such a way as to use conventional vinyl parts as coverings for the gate framing members. It would also be a substantial improvement in the art to completely enclose the gate members against weather. It would also be an advance in the aesthetics of the art to develop a framing system using metal in rigidizing vinyl gates while completely enclosing metallic components from view and from weathering.
What is needed is a method and apparatus suitable for creating a comparatively rigid, durable frame for operating with vinyl fencing materials to be sheathed with vinyl for weather protection and aesthetics. What is also needed is a system that minimizes the weight of metal, maximizes the stiffness and strength of the frame and of the overall gate, takes a minimum volume to ship, and is comparatively simple to assemble at a destination site.
In view of the foregoing, it is a primary object of the present invention to provide a system and method for a xe2x80x9cknock-downxe2x80x9d gate frame to be sheathed and assembled on site, during installation. In accordance with the invention, a gate framing apparatus and method are disclosed for supporting a plastic or other type of sheathed gate structure.
Consistent with the foregoing objects, and in accordance with the invention as embodied and broadly described herein, an apparatus and method are disclosed, in suitable detail to enable one of ordinary skill in the art to make and use the invention. In certain embodiments an apparatus and method in accordance with the present invention may include lateral beams, vertical beams, and comer ties. These components may all be sheathed with a polymer shell structure for aesthetics and wether protection.
A combination of cutting and braking the sheet metal parts, to form comers and beams having suitable rigidity, light weight, and being readily assembled into a frame. Moreover, due to the structures, and the method for manufacturing and assembling, the metal framing structure may be virtually completely enclosed within conventional vinyl extrusions used for fencing.
A vinyl gate framing system formed of sheet metal with a brake. Beams may be formed as channels. Perforations proximate each end of vertical channels may adapt the vertical channels to receive brackets. The brackets are formed by punching sheet metal to an appropriate shape and braking the blanks formed thereby into right-angled brackets. The right-angled brackets may be passed through the perforation in a backside of a vertical beams to fit between the sides of the channel of the vertical beam thus projecting inwardly to fit inside an end of a lateral channel beam.
Vinyl sleeves, even tubular vinyl sleeves may be slipped over all beams, lateral and vertical, before assembly. In one embodiment, no perforation is required in the vertical beams. Instead, a perforation in a vertical sleeve of a vertical beam is formed. Accordingly, a bracket is inserted into the perforation and thus into the channel of a vertical beam, where fastening such as riveting, bolting, welding, or the like may secure the same.
Meanwhile, an opposite end of the right-angled bracket penetrates through the perforation in the vertical vinyl sleeve to engage an end of a corresponding lateral channel extending away therefrom. Fasteners such as rivets, bolts, screws or the like may pass through the vinyl tubular channel surrounding a lateral beam to penetrate the lateral metal, braked beam and the laterally-extending leg of the right-angled bracket protruding from the vertical beam.
In certain embodiments, a gate frame may be comprised of sheet metal formed into channels and assembled into boxed, tubular structures. The gate comers may be rigidized by ties. Comer Ties, or just ties, may be configured as part of the gate frame members (beams), or as separate entities connecting horizontal and vertical gate frame members to one another. In certain embodiments, the gate frame materials may be formed as channels and remain substantially as channels except at certain highly loaded locations (e.g. comers). In other embodiments, the framing members (horizontal and vertical) may actually be doubled and fastened together in order to provide a box or tube formed by two interleaved channels.
Various methods and apparatus for tying comers of a gate frame are disclosed. In selected embodiments, each half of a tie may be a mirror image of the other half. The major portion of the tie may actually serve as a shear plate for supporting stresses in the comers of the gate. In other embodiments, the ties may be boxed together with channel members in order to provide a dimensionally stable, strong, rigid mechanical structure.